Since you don't have your RV model listed in your post, I'm going to assume you've got a toyhauler with a patio option.
The 'tarps' are gap closures that fit between the railing closest to the ramp opening, and the bodywork of the RV. If you've got small kids or pets, this keeps them from slipping and/or falling between the crack.
The white track fits over the lip of the panel in the rig, and the straps secure around the rail.
2013 VOLTAGE 3200 (EPIC I & II)
2014 Ford F-450 PLATINUM